Recently, a wearable device that can be worn on a user's body is increasing with improvement in computer performance, miniaturization of devices, and speed-up of communications. Specifically, once the user wears, for example, a wearable device with a sensor, the wearable device always senses pulses, walking conditions, and the like of the user, and can provide the status of the user to, for example, a smartphone owned by the user. Moreover, once the user wears, for example, an eyeglass-type wearable device with a display, the wearable device can display information provided from, for example, a smartphone so that the user easily visually recognizes the information.
By utilizing such wearable devices, it is expected to support operations in various fields. For example, in an inspection operation of devices, when the user stops in front of an inspection target device, even a user not skilled in the operation can efficiently carry out the working if inspection contents are displayed on the eyeglass-type wearable device. The support of these operations can be implemented by a device network system having, for example, a sensor device with a sensor, a display device with a display, and a mobile terminal such as a smartphone.
Specifically, the sensor device detects a status change, as a sensor event, such that the user starts walking and stops walking, and transmits the detected sensor event to the mobile terminal. The mobile terminal generates information corresponding to the sensor event received from the sensor device through processing according to an application in execution, and transmits the generated information to the display device. Then, the display device displays the information received from the mobile terminal.
Patent Literature 1: Japanese Laid-open Patent Publication No. 2013-5294
Patent Literature 2: Japanese Laid-open Patent Publication No. 2005-348203
However, in the device network system, the power consumption of the devices such as the sensor device, the display device, and the mobile terminal is not considered, and therefore, there is a problem that it is difficult to make an operating time sufficiently long. In other words, in the device network system, the mobile terminal operates an application to generate information and transmits the information to the display device each time a sensor event is received from the sensor device. Therefore, the mobile terminal consumes power each time the sensor event is received from the sensor device, and the operating time of the device network system is restricted by the battery capacity of the mobile terminal.
Therefore, it is also considered that the sensor device and the display device directly communicate with each other without passing through the mobile terminal. In this case, it may be configured that the mobile terminal previously performs initial settings for communication and display on the sensor device and the display device and that the sensor device and the display device directly communicate with each other to operate after the initial settings. Consequently, after the initial settings, it is possible to implement the support of operations for the user using the sensor device and the display device even if the mobile terminal does not operate.
However, because there are various devices and applications used for the device network system, the network configuration, in which the sensor device and the display device directly communicate with each other without the mobile terminal, is not always optimal. Moreover, battery capacities and remaining battery capacities of the devices are not always the same as each other, so that an optimal network configuration may be changed depending on the battery capacities and the remaining battery capacities of the devices. Therefore, it is not easy to make sufficiently long the operating time of the device network system in which various devices and applications are used.